St. Vincent of Lerins

It never was, is, or shall be lawful for Catholic Christians to teach any doctrine except that which they have received once and for all time; and it always was, is, and shall be their duty to condemn those who do . . . To detect the frauds and avoid the snares of heretics as they arise, and to continue whole and sound in the Catholic faith, we must, God help us, fortify our own belief in two ways: first, by the authority of Divine law, and then by the tradition of the Catholic Church . . . Since the canon of Scripture is complete, and more than sufficient of itself for everything, what need is there to join with it the authority of the Church's interpretation? . . . For this reason: because, owing to the depth of Holy Scripture, not everyone accepts it in one and the same sense ... Therefore, it is very necessary that the rule for the proper understanding of the Prophets and Apostles be framed in accordance with the standard of ecclesiastical and Catholic interpretation. Moreover, in the Church itself, every possible care must be taken to hold fast to that faith which has been believed everywhere, always, and by everyone. For that is truly and in the strictest sense "Catholic" which comprehends all universality . . . He is a true and genuine Catholic who loves the truth of God, who loves the Church, who loves the Body of Christ, who esteems Divine religion and the Catholic faith above everything: above the authority, the regard, the genius, the eloquence, the philosophy of every man whatsoever. He is a genuine Catholic who continues steadfast and well-founded in the faith, who resolves that he will believe those things-----and only those things-----which he is sure the Catholic Church has held universally and from ancient times . . . It is therefore an indispensable obligation for all Catholics who are eager to prove that they are true sons of Holy Mother the Church to adhere to the holy faith of the Fathers, to preserve it, to die for it, and, on the other hand, to detest the profane novelties of profane men, to dread them, to harass them, and to attack them.

St. Vincent of Lerins